Cylinder head
Note: Allow the engine to cool completely before starting the procedure.
Removal
1. Relieve the pressure in the fuel system (see chapter 4A), then disconnect the cable from the negative battery terminal.
2. Drain the coolant from the cylinder block and radiator (see Chapter 1A).
3. Drain the engine oil and remove the oil filter (see Chapter 1A).
4. Remove the air filter housing. Also remove the fuel rail and injectors (see chapter 4A).
5. Remove the intake manifold (see paragraph 5).
6. Remove the exhaust manifold (see paragraph 6).
7. Remove the timing belt, camshaft sprocket and upper tension roller (see paragraph 7).
8. Remove the rear timing belt cover.
Note: Also disconnect the camshaft position sensor.
9. Remove the camshafts and valve lifters (see paragraph 10).
10. Label and remove any remaining components such as cooling system connections, lines, control cables, hoses, or wiring harnesses (see Figure 5.5,a). The cylinder head is now ready for removal.
11. Using an 8-mm hex head-and-crank bit, loosen the cylinder head mounting bolts, making 1/4 turn in one pass, until they do not turn away with the force of your hand. Loosen the bolts in the reverse order to that shown in the figure 11.23, to prevent distortion of the mating surface and the appearance of cracks on the head body.
12. Carefully remove the head from the cylinder block upwards. If the head is stuck to the block, very carefully pry it up using a pry bar using the specially provided protruding lugs on the transmission side (see figure 11.12,a,b). Do not insert a pry bar between mating surfaces under any circumstances.
Figure 11.12,a. If the head is "fused" to the block, carefully pry it up using the special protruding lugs with a pry bar.
Figure 11.12,b. Components of the cylinder head and related units.
13. Remove all remaining external head parts, preparing it for cleaning.
Installation
14. Before installing the head, thoroughly clean the surfaces of the block connector and the head.
15. Using a soft scraper, remove traces of the old gasket and carbon deposits (see Figure 11.15), then wipe the mating surfaces with a rag soaked in varnish thinner or acetone.
Figure 11.15. Carefully remove any remaining old gasket and sealant - the mating surfaces of the cylinder head and block must be absolutely clean to ensure a good seal for the new gasket.
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If oil remains on the mating surfaces after the head is installed, this will lead to uneven compression of the gasket and cause leaks and burnouts. When working with the block, place a clean rag in the cylinders to prevent debris from getting into them. To clean the cylinders and channels of the block, use compressed air or a vacuum cleaner.
16. Inspect the head and block connector surfaces for nicks, deep scratches, and other damage. If the damage is minor, it can be removed with a file. Serious damage can only be repaired in a specialized workshop by grinding.
17. Tap the threads of the cylinder head bolt holes in the block, then clean the holes with compressed air or a vacuum cleaner.
Caution! When working with compressed air, wear a protective mask or goggles.
18. Using a wire brush, clean the threads of the mounting bolts from rust. Dirt, rust, sealant and damaged threads can cause incorrect tightening torque.
19. Put all the parts back in place, (which were removed from the cylinder head).
20. Place the new gasket, aligning the corresponding holes with the mounting pins on the block surface.
21. Being careful not to move the gasket, carefully install the head onto the cylinder block.
22. Before tightening, lubricate the threaded parts of the head bolts with a thin layer of engine oil.
23. Install the bolts in their places and tighten them by hand. Tighten the head bolts to the specified torque, strictly following the recommended tightening sequence (see Figure 11.23).
Figure 11.23. Cylinder head bolt tightening sequence.
Note: Be sure to lightly lubricate the threads and undersides of the bolt heads with engine oil and install washers.
24. Installation of the remaining components is the reverse procedure.
25. Check and adjust, if necessary, the clearances in the valve drive mechanism (see Chapter 1A).
26. Fill the cooling system, install a new oil filter and fill the engine with oil (see Chapter 1A).
27. Start the engine and warm it up to normal operating temperature. Make sure there are no leaks. Set the ignition timing (see chapter 5) and take a short test drive to check the engine's operation.